The party's ruling national executive committee met on Sunday and agreed to the timetable for both the leadership - and deputy leadership - contests.

Nominations for the contests will open on Monday at 1430 BST and close on Thursday at 1230 BST. There will be 10 hustings events before the results are announced at a special one day leadership conference in Manchester.

With Mr Blair having said he would step down as prime minister on 27 June, that means there will be three days when he is PM but someone else - almost certainly Mr Brown - is Labour leader.

Mr Brown will have to attend the hustings even if neither of his possible challengers, left-wing MPs Michael Meacher and John McDonnell, get backing from the 45 Labour MPs needed to enter the contest.

They claim that between them they can meet that figure and have said that the one with the least support will step aside in favour of the other.

Mrs Thatcher

As they continue to seek nominations from Labour MPs the two will debate policy with Mr Brown at a conference on Sunday evening.

Although Mr McDonnell told the BBC's Politics Show he believes he can beat Mr Brown, the two are not generally seen as a realistic threat to Mr Brown's chances.

And, although he defended it, he acknowledged there were "always lessons to learn" from criticism that he had indulged in spin in the Budget when he announced a headline 2p cut in the basic rate of tax, even though other changes meant many people would not be better off.

On the National Health Service he said "we've still got a lot to do to show people" it is moving "into the modern era... there for people when they need it".

He said he did not think the health service should be given full independence, saying ministers still needed to make funding decisions, but he talked up the local accountability allowed by foundation hospitals.

But for the Conservatives, the shadow health secretary Andrew Lansley said: "Gordon Brown is responsible for Labour's financial mismanagement of the NHS. He failed to make the NHS a priority during his 10 years as chancellor and his rhetoric... is unconvincing."